import java.util.Scanner;

public class 计算机直角三角形的面积 {
        public static void main(String[] args) {
                double a,b,c,s;
                Scanner sc =new Scanner(System.in);
                System.out.println("a=");
                a=sc.nextDouble();
                System.out.println("b=");
                b=sc.nextDouble();
                System.out.println("c=");
                c=sc.nextDouble();
              //  s = (a,b,c);
        }
 }
